Induction solder-pot heater



0. A. COLBY.

INDUCTION SOLDER POT HEATER.

APPLICATION FILED DEC.13.1919.

Patented Sept. 14, 1920 INVENTOR I I am. Cafig INDUCTION SOLDER-POT HEATER.

Specification of Letters Patent.

Application filed December 13, 1919. Serial No. 344,660.

To all whom it may concern:

Be it known that I, ORA A. COLBY, a citizen of the United States, and a resident of Irwin, in the county of Westmoreland and State of Pennsylvania, have invented a new and useful Improvement in Induction Solder-Pot Heaters of which the following is a specification.

y invention relates to electrically-heated apparatus and particularly to electricallyheated solder pots, and it has for an object to provide a simple and compact heating device for solder pots of relatively large size, comprising a grid resistor so arranged as to be non-inductive and which may be easily and quickly removed from its supports.

More specifically, my invention embodies a heat-insulating supporting frame having a central 'hollowportion in which is suspended a Solder pot. A zigzag grid resistor having a relatively large area of crosssection is so mounted in ,the supporting frame as to be easily and quickly removable as a whole. A transformer is mounted on or near the supporting frame and is provided with a secondary winding having a relatively. low voltage and connected to the grid resistor.

Referring to the single sheet of drawings, Figure 1 is a top plan view, partly in crosssection, of a device embodying my invention; Fig. 2 is a vertical cross-sectional View on the line 11, II of Fig. 1; Fig. 3 is a schematic vertical cross-sectional view of a device embodying my invention and showing particularly the arrangement and connection of the resistor; Fig. 4 is a top plan view of one of the grids, and Fig. 5 is a side elevation thereof.

metal container 1, which maybe of any suitable contour, is here shown as a square box. An inner lining 2 of suitable refractory material, such, for example, as fire brick, is so arranged in the box-1 as 0 provide a space 3 between it and the box which may be filled with a heat-insulating material 4, such, for example, as mineral wool. 'A substantially cylindrical central well 5 is provided within the lining 2. A cover member 6 is mounted on the top of the box 1 and is provided with a central circular opening 7 coaxial with the solder pot 8 is suspended in the well 5 through the opening 7.

spaced relation The solder pot 8 is smaller than theinner well 5 in the vide an annular space in which is located a heating element 9 which comprises a plurality of separate grid resistors 10, as best. shown in F lgs. 4 and 5. The grids 10 may be made of cast metal of relatively large cross-sectional area, having a zigzag arcuate form and being provided with a short radlal extension 11 at one end and with a somewhat longer radial extension 12 at the other end, each of these extensions being provided with a circular opening 13. Each grid extends over somewhat less than 90 of arc, and ten of these grids may be bolted together by means of bolts 14, as shown in Fig. 1, to form a resistor which embraces substantially one and one-quarter turns around the solder pot 8 in one direction and then one and one-quarter turns in the opposite direction. A plurality of vertical radial apertures 15 are provi'ded'in the firebrick lining 2, each of these having two lateral openings 16, as shown in Fig. 2. The lateral openings 16 provide supporting ledges which cooperate with the extensions 12 to support the heating element 9 in to the pot 8 in the well 5.

A transformer 17 may be mounted on a suitable supporting frame 18 which is mounted on the side of the container 1 and comprises the usual high-tension winding 9, a magnetic core 20 and a low-tension winding 21 having relatively few turns of heavy conductor, the last-named winding being connected to the heating element 9 by means of heavy metal bars 22 and clamping bolts 23. The transformer 17 may be separately mounted in close proximity to the container 1, if desired.

It Will be noted that the grid resistorsgi're self-sustaining between the supportingextensions 12 and that their zigzag shape permits a relatively large portion of the surface of the solder pot to be acted upon by the heat generated by them. The complete heating element comprises a number of sections of the grid 10, all of which may be castfrom the same pattern. The heating element is substantially reason of being return-wound upon itself.

The solder pot may be easily and quickly removed by lifting it out of its support. The complete heating element may be taken out, after the solder pot and the cover have been Patented Sept. 14, 1920.

non-inductive by' fire brick lining so as to proremoved, by first removing the bolts which hold it to the connecting bars 22 and then giving the heating element a small rotative movement to'bring the projections 12 into the open vertical part of the wells 15, after which it may be lifted out vertically. The thermal efiiciency of the device will be relatively high because of the heat-insulating materials used in the construction thereof.

Various modifications may be made in the device without departing from the spirit and scope of my invention, and I desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art or are specifically set forth in the appended claims.

I claim as my invention:

1. In an electrically-heated apparatus, the combination with a container, of a source of electromotive force, a resistor connected thereto, said resistor surrounding said container, and means on said resistor for supporting the same.

2. In an electrically-heated apparatus, the combination with a container, supporting means therefor, and a source of electromotive force, of a grid resistor connected to said source of electromotive force and surrounding said container, and means on said resistor for supporting it from the said container supporting-means.

3. In an electrically-heated apparatus, the

combination with a container, and supporting means therefor, of a transformer having a low-voltage secondary winding, a grid resistor connected to said secondary winding and embodying means on said resistor for supporting it in spaced relation between said container and the supporting means.

4;. In an electrically-heated apparatus, the

" combination with a container and supporting means therefor, of'a transformer having primary and secondary windings, a grid resistor connected to the secondary winding of said. transformer, said resistor being wound first in one direction around said container and then wound in the reverse direction a substantially equal number of turns, and means on said resistor for supporting it on said supporting means.

5. In an electrically-heated apparatus, the combination with a container, supporting means therefor and a source of electromotive force, of a grid resistor connected to said source of electromotive force and Wound non-inductively around said container, and

number of turns in one direction and then wound substantially the same number of turns in the reverse directlon, and means on said resistor for mounting the said resistor on said supporting means in spaced relation between said container and said supporting means.

7 In an electrically-heated apparatus, the combination with a container,-a surrounding heat-insulating supporting means for said container and a source of electromotive force, of a grid resistor connected to the source of electromotive force said resistor being wound around said container a certain number of turns in one direction and then substantially the same number of turns in the reverse direction and means for mounting said resistor on said supporting means in spaced relation between said container and said supporting means.

8. In an electrically-heated apparatus, the,

combination with a container, of a resistance element comprising arc-shaped members of' zigzag form bolted together.

9. In an electrically-heated apparatus, the

combination with a container, of a non-inductive resistor winding embodying arcshaped members, said members being assembled to provide a certain number ofturns in one direction and then substantially the same number of turns in the opposite direction.

vember 1919.

ORA A. COLBY. 

